Sonic apparatus for material separation



Feb. 5,: 1963 A. G. Booms, JR 3,076,547

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SONIC APPARATUS FOR MATERIAL SEPARATION Original Filed Sept. 29. 1959 2Sheets-Sheet 2 IN VEN TOR. N

United States Patent 3,076,547 SONIC APPARATUS FOR MATERIAL SEPARATIONAlbert G. Bodinc, Jr., Sherman Oaks, Calif. (3300 Cahuenga Blvd., LosAngeles 28, Calif.)

Original application Sept. 29, 1959, Ser. No. 843,269.

Doitgged and this application Oct. 5, 1960, Ser. No.

2 Claims. (Cl. 20920) This invention relates generally to materialmoving and/ or separating apparatus operating by sonic principles, andhas application in a number of fields, including, among others:classification and separation of granular materials of differentdensities, or particle size, for example, separation of metals from ore.

A general object of the invention is to perform such functions andoperations through use of propulsive forces generated in simple acousticapparatus in which powerful acoustic standing waves of high accelerationfactor are maintained.

The invention in its various aspects depends upon materials motivatingforces occurring between the nodes and anti-nodes of an acousticstanding wave. These forces operate differentially, in apparatusaccording to the invention, or particles of different densities and/ orparticle size. Apparatus in accordance with the invention utilizes suchforces to separate or classify heterogeneous mixtures of materials ofdifferent densities and/or particle size, for example, metals from ores.

In addition to the motivating force, and apparently of equal importance,is a particle agglomerating compulsion which arises by reason of waveaction on the material. The oscillation of the particles of the materialowing to this wave action occurs with an acceleration many times that ofthe acceleration of gravity, causing particles of like density toagglomerate. The agglomerated body of like-density, particulate materialis then readily separated out of the carrier material. Such body travelslongitudinally of the standing wave under the influence of theabove-mentioned propulsive force between nodes and anti-nodes, and tendsalso to separate out of lighter carrier material by gravity. Theover-all propulsive and separative force availed of by the invention isthus the resultant of both physical phenomena.

With this brief preliminary discussion in mind, the invention may bestbe further described in connection with the following detaileddescription of a number of typical forms and embodiments thereof,reference for this purpose being had to the accompanying drawings, inwhich:

FIG. 1 is a vertical medial section of a form of the invention;

FIG. 2 is a top plan view of the apparatus of FIG. 1; and

FIG. 3 is a section on broken line 33 of FIG. 1.

In FIGS. 1 to 3 is shown a species of sonic separator in accordance withthe invention designed to carry out my sonic process of separatingmetallic constituents from ore which has been reduced to a granularstate. The apparatus heredisclosed was specifically designed for and hasdemonstrated substantial effectiveness in the separation of uraniumsalts from ore. However, while I will refer to such materialshereinafter, no limitation thereto is to be implied.

A generally cylindric vessel 10 is provided, having an outer imperforateside wall 11, and an inner perforated wall 12 annularly spaced insidethe wall 11. Wall 12 defines the side of an annular treatment chamber13. The annular space between Walls 11 and 12 is packed with soundabsorbent material, such as fibreglass packing 14. A ring-plate 15 iswelded to the lower edges of plates 11 and 12, and immediately belowplate 15 is a similar ring-plate 16. These ring-plates project outwardlybeyond side wall 11, providing flanges which are bolted together, asindicated. The vessel is supported by legs 17 engaging under and weldedto plate 16. A cylindric wall 18, of the same diameter as wall 11,extends downwardly from ring-plate 16 immediately inside legs 17, beingwelded at the top to member 16. A bottom ringplate 19 is welded to andextends inwardly from the lower edge of wall 18 and a perforatedfrusto-conical wall 20 is welded at the top to the inner edge of ring16, and extends downwardly and inwardly therefrom to meet the inner edgeof ring-plate 19, as shown best in FIG. 3. Fibreglass sound absorptionpacking 21 is placed in the annular space defined by the members 16, 18,19 and 20, as indicated. Secured to the inner periphery of ring-plate 19is a frusto-conical wall 22 forming a continuation of wall 20, to whichis joined a materials outlet and air inlet tube 23. A frusto-conicalwall 24 is mounted slightly inside perforated wall 20, and shields thelatter from downwardly discharging material.

Welded to the top of walls 11 and 12 is a ring-plate 26, engaged by aring-plate 27 of the removable top 28 of the vessel, the projectingflange portions of plates 26 and 27 being bolted together, as indicated.The top of 28 comprises an exterior cylindric side wall 29 welded to andrising from ring-plate 27, a top wall 30 extending inwardly from theupper edge ofsidewall 29 and formed with a central opening 31, adepending cylindric wall 32 located somewhat outwardly from opening 31,and a perforate wall 33, joining the lower end of wall 32 with the inneredge of ring-plate 27. The annular space so formed is packed withfibreglass 34, also for sound absorption purposes.

A short vertical wall 40 rises from top wall 30, just outwardly ofopening 31, and mounted on the top portion of the latter is a louveredchamber 41, equipped with a top 42, from which leads outlet pipe 43. Thelatter is coupled by flexible coupling 44, such as a rubber hose, to apipe 45 leading to the inlet of a blower 46. Chamber 41 has sidewalls 47formed with air louvers 48, anda lower conical portion 49 formed withlouvers 50. Rising from the inner edge of the latter is a generallyconical shield 51.

A plurality of vertical cylindrically shaped rubber posts 55 are mountedin cylinders 56 secured to lower ringplate 19, as by welding, thesebeing located adjacent the inner periphery of the latter, asillustrated. The lowermost of a vertical series of horizontal, circular,steel vibratory plates 58 rests on and is secured to the rubber posts55. For example, an insert 59 molded in the upper end of each post 55has a projecting stud 60 passing through plate 58, a nut 61 screwed onthe upper end of the stud securing the plate 58 in assembly with therubber post. The plates 58 are spaced by means of slotted spacer sleeves62. The slots 62a and 62b extending inwardly from opposite ends of thesleeves, and preferably staggered, as indicated, are simply to give thesleeves a desirable degree of flexibility.

A vibrator shaft 65 extends vertically through central apertures 66 inplates 58 and through the aforementioned spacer sleeves 62, having onits lower end a flange 67 to which is bolted vibration generator 68. Aspacer sleeve 69, slotted downwardly part way, as at 70, is placed onshaft 65 between lowermost plate 58 and shaft flange 67; and a spacersleeve 71, slotted part way up from the bottom, is placed on shaft 65above uppermost plate 58. The upper extremity 73 of shaft 65 is reducedand screw-threaded, and a nut 74 threaded thereon is set up tightly andholds the parts in assembly, serving to clamp vibration generator 68securely to the set of plates 58.

An eye '75 on the upper end of shaft 65 permits convenient lifting ofsaid shaft together with the assembly of plates 58.

T he generator 68 may be of various types, provided sufficient power isprovided. That her-e shown (FIGS. 1 and 3) provides the large outputpower required by the invention in a simple manner. The generatorembodies a housing 80 bolted to the aforementioned shaft flange 67,carrying bearings for two parallel shafts 81 and 81. Tightly mounted onthese two shafts are spur gears 82 and 83, respectively, meshing witheach other, and carrying eccentric weights 84; and shaft 81 is coupledto a drive shaft 85 driven from any suitable prime mover, such as anelectric motor, not shown. The shaft 85, as shown in FIG. 3, projectsoutside the apparatus through suitable openings. The weights 84 arephased so as to move vertically in unison. Hence, their unbalancedcomponents of centrifugal force are additive vertically, exerting avertically directed oscillating force through the shaft hearings to thegenerator housing and thence to the vertical shaft 65. It will be seen,however, that the unbalanced weights 84 develop horizontal components offorces which are always equal and opposed, and that these components offorce are therefore cancelled. Generator 6% accordingly, acting throughshaft 65 and the several spacer sleeves, exerts a vertically directedoscillating force on the inner peripheries of the plates 58. The latterare of a good grade of elastic steel, and are set into a mode ofstanding wave vibration when generator 68 is driven at proper frequency,in a manner to be more fully explained presently.

Suspended from plates 58, as by means of U-bent flat spring elements 90,are upwardly concave bafiie plates 91, formed with central apertures 92of a diameter substantially larger than the outside diameter of thespacer sleeves 62. The outside diameter of the dish members 91 exceedsthe outside diameter of the plates 58 sufliciently to catch materialfalling off the peripheries of the plates 58, and are only narrowlyspaced from the vessel wall 12. The baffle plates 91 are also suspendedsufficiently far below the plates 58 to accommodate any relativevibration between the members 58 and 91 so that these members will notstrike one another during the operation of the apparatus.

The vessel is completed by a plurality of material inlets 100 extendingthrough top wall 30, as shown, and discharging well inwardly on theuppermost plate 58.

It has been described how vibration generator 68, acting through post orshaft 65, exerts a vertically oscillating force on the inner peripheryof the plates 58, i.e., in a direction normal to the plates. Thisaction, when generator 68 is driven at proper frequency, sets theseveral plates 58 into a mode or pattern of standing wave vibration,characterized by an alternating upward and downward elastic bowing ofthe plates. In this pattern, there is an elastic vertical oscillation ofthe inner or central region of the plate, a similar elastic verticaloscillation, but of opposite phase, of the outer or rim portion of theplate, and an annular nodal region of minimized or zero oscillationbetween the two. In the apparatus as disclosed in the figures, the nodalregion of minimized oscillation, designated N, is at or just slightlyoutside the point of mounting of the lower-most plate 58 to the rubberposts 55. Thus, at this region, the elastic deflection amplitude of theplates is minimized, and the vibratory deflection amplitude increasesprogressively in both directions, inward and outward, to maximums at itsinner and outer edges. These edge regions are at velocity antinodes ofthe vibration pattern, designated by V and V respectively. In otherwords, the plate flexes elastically, deflecting upwardly at its centralvelocity antinode region while deflecting downwardly in its outervelocity antinode region, and then downwardly in the central region andupwardly in its outer region, while the intermediate nodal regionremains substantially stationary. To accomplish this standing wavevibration, the generator 68 is driven at the fundamental resonantfrequency of the plates for the desired vibration pattern. Higherharmonics may be used, if desired, by driving the generator at multiplesof the fundamental frequency.

In operation, the material to be separated is introduced, preferablycontinuously, through the inlet 100. This entering material, which forexample may be a uranium ore, is preliminarily pulverized to arelatively fine grain size. In my work with the apparatus shown in FIGS.1 to 3, I have found that optimum results are obtained with the enteringmaterial pulverized to a maximum grain size of the order of inch. Thisis mentioned, however, by way of example, and without intention oflimitation. The material so introduced to the vessel falls on theuppermost plate 58 somewhat inwardly of the nodal region.

The blower 46 is operated, and draws a strong current of air through thevessel, in through tube 23 at the bottom, out through louvers 48 and 50at the top, and thence via pipes 4-3 and 45 to and through the blower.Broadly, the purpose is to create an air flow which will pick up thelight particles of uranium salts which have been spaciallydifferentiated from the pulverized ore owing to the standing wavevibration of plates 58 over which the ore passes downwardly insuccession. Various upward air flow patterns may be used. The presentapparatus, however, has been contrived such that a substantialproportion of the air travelling upwardly through the vessel around theplates '58 and batlles 9'1 is diverted radially inward so as to sweepover the plates 58, and then pass upwardly through the central apertures92 in the baffles 91, and then travel radially outward between the uppersides of the battles and the plates 58 immediately above, in the patternsuggested by the arrows in FIG. 1.

As stated above, the incoming granular material falls from inlet ontouppermost plate 58 at a point which may be somewhat inward from node N.The plate 58, vibrating in the standing wave pattern previouslydescribed, has a component of vibration normal to its upper surfacewhich is in contact with the granular material supported thereon. Thiscomponent of vibration of the plate takes place with high acousticpower, and with an acceleration many times that of gravity. Under theinfluence thereof, the different granular materials, e.g., carrier oreand uranium salts, are differentially motivated and agglomerate. Thematerials, under the severe sonic agitation, may be observed to becomedynamically suspended or sustained in a free flowing condition like aliquid. The materials move toward the nodal region N, where vibrationamplitude is minimized, and the lighter or more finely dividedconstituent, which is the uranium salt desired to be recovered,simultaneously rises to the top. The precise mechanism by which thisperformance occurs is still somewhat obscure, and acoustics experts whohave observed the phenomena differ somewhat as its precise nature. Inthe foregoing, I have given the best explanation known to me. However,the phenomena described are readily observed, and occur when the plate58 is vibrated with suficient acoustic power to produce a highacceleration factor, whence the materials can be seen to be in a highlyagitated, dynamically sustained and free flowing state, moving to allintents and purposes substantially as freely as a liquid.

The material on the plate 58 can be observed to form an annular mound,such as indicated X, highest over the nodal region. As this mound buildsup, athin edge of the material spills radially outward, and falls overthe peripheral edge of the vibrating plate, to be caught by the bafiieplate 91 immediately below. The lighter or more finely dividedconstituent, i.e., the uranium salt, moves to the top of the mound, andforms a dust cloud thereover. This differential material, partly risingin a cloud and partly residing at the surface of the mound in adynamically sustained state, is caught up by the air current flowingradially inward over the plate 58, and is discharged with the air viathe blower.

The material spilling over the edge of the plate 58 onto the bafileplate 91 still contains a substantial amount of the salt to berecovered. This material slides down the bafiie member, aided byvibration of the latter owing to its spring suspension from thevibrating plate, and falls through aperture 92 onto the plate 58immediately below. There the performance is repeated, the materialmigrating, under the standing wave of the plate, to the nodal region,where it forms a mound, and spilling oif the edge of the plate when themound becomes high enough that its natural slope, under the sonicagitation, causes the material to reach the edge. Again the lighter orfiner particles move to the top, and are picked up by the air currentover the plate, to be separated out.

Thus recovery is progressive, the ore giving up a proportion of itsmetallic constituent at each plate 58. The remaining ore going oil thelowermost plate 58 is caught within the conical bottom portion of theapparatus, and discharged at 23.

The material so discharged may still contain a valuable proportion ofrecoverable mineral, and may be run through a second similar separator.Also, the separated material going off through the blower may stillcontain a substantial proportion of the carrier ore, and may besubjected to further separative treatment.

Granular uranium ore may contain particles of carrier ore, and particlesof uranium salt. The particles of carrier ore may also have adheringthereto substantial amounts of uranium salt. In the course of the sonicagitation of the material within the apparatus, the uranium saltadhering to the particles of carrier ore is largely abraded away, andbecomes a fine dust. Grains of uranium salt initially present are alsoreduced to a fine size in the process, and the salt is recovered in afinely divided form.

The previously mentioned air flow paths through the vessel are in no waycritical. It is merely necessary to provide unidirectional air movementthrough all parts of the main chamber of the machine, so that the dustcloud of uranium salts which have been sonically separated from theparent ore by the above described mechanism, and which have becomethrown up from the plates and reside in a dynamically sustained state atthe top of the ore bodies on the plates will be transported to acollection point. Many standard forms of dust collectors can be employedat the collection point, to remove the uranium material from the airstream.

This application is a division of my prior application entitled SonicMaterials Separation Process and Apparatus, Serial No. 843,269, filedSeptember 29, 1959, now abandoned.

The invention has now been shown in an illustrative form. It will ofcourse be understood that this is for illustrative purposes only, andthat many variations in design, structure and arrangement are possiblewithin the scope of the appended claims.

I claim:

1. In an apparatus for separating unlike granular particles, thecombination of: a stack of vertically spaced, generally horizontallydisposed elastic disks, said disks being elastically vibratory in afiexural mode at one common resonant frequency, means structurally andsubstantially rigidly uniting the central portions of the disks of saidstack to one another, a vibrator connected to said uniting means forvibrating said means vertically at said resonant frequency, so as toinduce high amplitude resonant fiexural vibration of said disks, meansfor feeding said materials to the uppermost of said disks, sloping, flowdirecting bafiles located between said disks and extending from outsidethe peripheral edge line of the disks to a region inwardly thereof andabove the disk below, whereby overflow off the peripheries of the disksis delivered to the disks below by gravity flow, a housing around saiddisks for confining dust created by the vibration of the plates, saidhousing having an opening in the lower portion thereof for dischargingthe overflow from the lowermost of the disks, and an air and dustconduit connected to the upper portion of said housing for dischargingsaid dust.

2. in an apparatus for separating unlike granular materials thecombination of: a stack of vertically spaced, generally horizontallydisposed elastic disks, each having a central hole therein, said disksbeing elastically vibrat-ory in a flexural mode at one common resonantfrequency, a vertical post extending through said holes in said disksand rigidly fastened to said disks adjacent said holes, a vibratorconnected to said vertical post for vibrating said post vertically atsaid resonant frequency, so as to induct high amplitude resonantflexural vibration of said disks, means for feeding said materials tothe uppermost of said disks, sloping, flow directing batfies locatedbetween said disks and extending from outside the peripheral edge lineof the disks to a region inwardly thereof and above the disk below,whereby overflow off the peripheries of the disks is delivered to thedisks below by gravity flow, a housing around said disks for confiningdust created by the vibration of the plates, said housing having anopening in the lower portion thereof for discharging the overflow fromthe lowermost of the disks, and an air and dust conduit connected to theupper portion of said housing for discharging said dust.

References Cited in the file of this patent UNITED STATES PATENTS1,983,968 Clark Dec. H, 1934 2,071,260 Holden Feb. 16, 1937 2,591,083Maier Apr. 1, 1952 2,755,927 Brooks July 24, 1956 2,766,881 WesterveltOct. 16, 1956 FOREIGN PATENTS 508,675 Great Britain June 26, 1939718,588 Great Britain Nov. 17, 1954

1. IN AN APPARATUS FOR SEPARATING UNLIKE GRANULAR PARTICLES, THECOMBINATION OF: A STACK OF VERTICALLY SPACED, GENERALLY HORIZONTALLYDISPOSED ELASTIC DISKS, SAID DISKS BEING ELASTICALLY VIBRATORY IN AFLEXURAL MODE AT ONE COMMON RESONANT FREQUENCY, MEANS STRUCTURALLY ANDSUBSTANTIALLY RIGIDLY UNITING THE CENTRAL PORTIONS OF THE DISKS OF SAIDSTACK TO ONE ANOTHER, A VIBRATOR CONNECTED TO SAID UNITING MEANS FORVIBRATING SAID MEANS VERTICALLY AT SAID RESONANT FREQUENCY, SO AS TOINDUCE HIGH AMPLITUDE RESONANT FLEXURAL VIBRATION OF SAID DISKS, MEANSFOR FEEDING SAID MATERIALS TO THE UPPERMOST OF SAID DISKS, SLOPING, FLOWDIRECTING BAFFLES LOCATED BETWEEN SAID DISKS AND EXTENDING FROM OUTSIDETHE PERIPHERAL EDGE LINE OF THE DISKS TO A REGION INWARDLY THEREOF ANDABOVE THE DISK BELOW, WHEREBY OVERFLOW OFF THE PERIPHERIES OF THE DISKSIS DELIVERED TO THE DISKS BELOW BY GRAVITY FLOW, A HOUSING AROUND SAIDDISKS FOR CONFINING DUST CREATED BY THE VIBRATION OF THE PLATES, SAIDHOUSING HAVING AN OPENING IN THE LOWER PORTION THEREOF FOR DISCHARGINGTHE OVERFLOW FROM THE LOWERMOST OF THE DISKS, AND AN AIR AND DUST